A thermo-graphic camera, or infrared camera, forms an image using infrared radiation. Infrared cameras operate in wavelengths as long as 14,000 nm (14 μm). Many infrared cameras incorporate a cooled detector to capture the infrared image. Cooled detectors are typically contained in a dewar, or vacuum-sealed case, and are cryogenically cooled. Cooling is necessary for the operation of the semiconductor materials used. Cooled detectors typically operate in a range from 60 Kelvins (K) to 100K, with some operating in a range from 4K to room temperature. Cooling is power-hungry and time-consuming. The camera may need several minutes to cool down before it can begin working.